hey guys are driving home today and noticed that the transmission temperature was rising higher than usual I do have an external transmission filter and this 6.0l transmission cooler I believe its 26 row and I've only been running about 130 140 in today it was running about 170 to 180 that's definitely not normal for this truck especially after I put the new cooler on it, it could be because it's colder out but I did notice one thing with the external filter that it is not getting hot I would think that the filter would be filtering hot oil through it and it would become hot as well, all the lines and the filter were very cold.

One thing i am very confused about is why the transmission filter is very cold and also the lines. I bought this external filter from Bob at dieselsite and I believe its a hundred thousand miles before you have to change the filter, now the filter could be plugged but I don't believe that's the case since I did change the a transmission oil and I install the external filter at the same time so I did give him a call I'm waiting on his call back.

here's a picture of the gauges and my scan gauge what everything was reading.





Any help is welcome!

AJ

 

I have installed an external and my temps have increased 10-20 degrees from what they used to be. This is without towing, don't know what will happen when hook onto 5th wheel. Internal filter was not removed.

 

Do NOT remove the internal filter! That's a disaster waiting to happen.

What trans fluid are you using? Synthetic or conventional? HOw cold is the ambient temperature?

 

I'm using i believe conventional, when i changed the fluid i called Napa and asked for OEM fluid, it was Napa brand but it was what is suppose to be used. And ambient was about 5 degrees with wind. I have had the external filter and new fluid with the cooler for about a year now with know problems. Now i can't say i saw am increases in temp just from the external but i can say when i installed the cooler and filter i dropped an easy 50 to 60 degrees this is the first time the temp rose this high without towing, even when i tow i never see these temps.

 

But what was the ambient? Wind only matters on exposed skin. A truck doesn't have any skin so wind doesn't matter.

 

I'm sorry i didn't specify enough it was 5 degrees and there was wind. I didn't mean the wind chill. Once again i do apologize for not specifying correctly.

 

On this same subject, does the flow to the cooler/external filter get shut off when the fluid temp is too low? I seem to remember Mark has mentioned using room temp fluid when changing tranny fluid using his flushing method. You would think that 170* fluid would be warm enough to be going through the cooler even if there is a temperature controlled valve. I seem to remember reading about that being a possible failure point on the 4R100.
You are smart to avoid towing until you figure this one out. Another slim possiblility you mentioned was a plugged filter-filters are cheap compared to a pump or tranny.
I suppose you have already thought about pulling loose the return line and putting a hose into a bucket to check for amount of flow per minute at idle-Mark could help with amount. Good luck, Larry

 

170* is not "outrageous". I use ambient + 100* but that is 50* - 100* - I have noticed my PCM is about 10* higher than my alalog; which consistently reports 160*.

I know the 4R100's have a temperature check valve that sometimes malfunction. Perhaps someone else can chime in as I have no experience with that particular valve.

The external media may have picked up contaminates restricting flow?

I would perform a Flow test to ensure the pump is operating correctly and there is no restriction in the lines. With an external filter it's just a 10 minute job.

Conventional vs Synthetic - I would suggest using whatever the manufacturer recommends including change intervals. Mark would be the go to guy for all this.

 

What I think is happening is that the fluid in the air to oil cooler is jelling. This usually happens just below 0°F, maybe the NAPA fluid is just a touch thicker. I recommend a piece of cardboard to cover the air to oil cooler. Cover the whole cooler, it doesn't need to see any cool air at those temperatures.

Not on purpose. If the fluid gets too thick it won't flow through the cooler and then the bypass opens.

You would think that. I did, too. Then one of my coworkers ran a test that proved that once the fluid jells in the air to oil cooler it won't flow again until the ambient warms up, no matter how hot the trans gets.

That's the temperature the trans was designed to operate at. You could call that the ideal temperature.

And I know that the 4R100 DOES NOT have a temperature check valve.
Ford has no recommendation of conventional vs synthetic. Ford recommends MERCON V fluid. You can get MERCON V in conventional, blend, or full synthetic.

Synthetic would most likely fix this issue. It will not jell at any temperature you're likely to ever see. A piece of cardboard is a much cheaper fix.

 

[QUOTE=Mark Kovalsky;13929788]What I think is happening is that the fluid in the air to oil cooler is jelling. This usually happens just below 0°F, maybe the NAPA fluid is just a touch thicker. I recommend a piece of cardboard to cover the air to oil cooler. Cover the whole cooler, it doesn't need to see any cool air at those temperatures.


Mark, how does this keep the oil from jelling? As you have stated wind chill does not change how cold the oil is in the cooler. If it jells below 0 how will this help. It will be jelled when you start the truck in the morning.

 

Mark thank you got the knowledge! Now you say a piece of cardboard but i am running a fia winter front grill cover. Should i also put a piece of cardboard over just the Trans cooler?

 

If you already have a cover then I don't think cardboard is going to help.

If you are not towing and the trans isn't getting over 220°F then you really don't have to do anything. It won't hurt it to bypass the coolers when it's this cold. If the trans is staying at 170°F everything is fine.

If you want to fix this and have your trans run too cold like most transmissions do, change to synthetic ATF.

 

Sounds good thank you very much!

 

Mark,
At what temp should the Trans fluid not gel? The ambient today was about 25.

Thank you,
AJ

 

If it is a good quality fluid it won't gel above 0F.